Boats are often used for various purposes. One purpose for which many small boats are used is simply pleasure. Pleasure boats, to be truly enjoyable, should provide the user with a mode of water transportation which is simple and convenient to use and, most importantly, efficient.
One source of inefficiency in many small boats is the use of a rudder to steer the boat. To get around this, various propeller drives have been devised in which the propeller is pivotable about a vertical axis so that the propeller can be pointed in the direction of desired thrust. See, for example, U.S. Pat. Nos. 1,826,507; 2,487,195; 2,956,535; and 3,377,976. However, these prior art steerable propeller drives all required constant attention to steering by the operator.